Irregularities in the terrain over which a tracked vehicle (such as a snowmobile) travels produce displacements and deflections of its suspension assembly. A conventional suspension supports an endless track, which is tensioned to surround a pair of parallel slide rails, a plurality of idler wheels and at least one drive wheel or sprocket. A shock absorbing mechanism involving springs, hydraulic dampers, and/or other shock absorbing elements, urges the slide frame assembly and the chassis (also known as a frame) of the tracked vehicle apart, against the weight supported above the suspension in a static condition.
When an irregularity such as a bump occurs on the terrain, the suspension allows the slide rails to move toward the tunnel. Similarly, when a depression occurs on the terrain, the suspension allows the slide rails to move away from the tunnel. In some cases, the terrain provides configurations for which the current tracked vehicles (and snowmobiles in particular) cannot or can only minimally accommodate. This is the case, for example, when the tracked vehicle is side-hilling. A tracked vehicle is said to be side-hilling when it is positioned at least partially sideways on a slope. In such a position, an uphill part of the suspension is disposed vertically above a downhill part of the suspension. This can increase the resistance to lean the tracked vehicle into the slope to keep the tracked vehicle horizontal.
Therefore, there is a need for a suspension assembly for a tracked vehicle that allows the tracked vehicle to drive on different terrain configurations. There is also a need for a tracked vehicle having such a suspension.